Question

I tied the event onchange to my textbox control:

var tbValue = document.getElementById("tbValue");
    tbValue.onchange = function () {
        var tbSelText = document.getElementById("selectText");
        if (tbValue.value == null) {
            tbSelText.value.replace("sada", "");
        }
        else {
            tbSelText.value.replace("sada", "sada" + tbValue.value + "'");
        }
    }

When I change tbValue (it’s my textbox control with onchange event) tbSelText must change at the same time. But it doesn’t.
What I did wrong?

Answer 1

I am guessing that you’re expecting the onchange event to fire while typing, which is not going to happen.

The onchange event only fires when the textbox losses focus (in other words, it blurs) AND if the content has changed. See this MSDN for information…

This event is fired when the contents are committed and not while the value is changing. For example, on a text box, this event is not fired while the user is typing, but rather when the user commits the change by leaving the text box that has focus.

If you want an event while typing you should look at one of the onkeydown, onkeypress or onkeydown events.